Method and device for monitoring film quality in film vacuum deposition process

Abstract

The invention relates to the technical field of photoluminescence materials, and particularly discloses a film quality monitoring method in a film vacuum deposition process, and the method comprises the following steps: in the film vacuum deposition process, measuring the photoluminescence intensity of a film and the real-time intensity of exciting light; calculating the relative photoluminescence quantum efficiency based on the photoluminescence intensity and the real-time intensity of the exciting light; and monitoring the film forming quality of the thin film based on the relative photoluminescence quantum efficiency, and determining an optimal deposition condition. According to the method for monitoring the quality of the thin film in the vacuum deposition process, the relative photoluminescence quantum efficiency of the thin film in the vacuum deposition process is calculated based on the measured photoluminescence intensity of the thin film in the vacuum deposition process and the real-time intensity of the exciting light; and the film forming quality of the film is monitored through the relative photoluminescence quantum efficiency, and the optimal deposition condition is further determined.

Description

Technical Field

[0001] The invention relates to the technical field of photoluminescent materials, and in particular to a method and a device for monitoring film quality during vacuum film deposition. Background Art

[0002] With the rapid development of advanced thin film technology, new materials for photoluminescence have been widely studied. Whether it is an inorganic semiconductor, an organic semiconductor, or an organic-inorganic hybrid perovskite or other semiconductor materials, the quality of its luminescence performance can be measured by photoluminescence intensity and photoluminescence quantum efficiency (PLQE). At present, when various vacuum thin film deposition methods are used to prepare thin films for different material systems, it is impossible to determine the preparation conditions when the film quality is optimal. In order to obtain high-quality thin films, it is necessary to monitor the in-situ photoluminescence and relative photoluminescence quantum efficiency (PLQE) of the thin film during vacuum deposition.

[0003] The existing monitoring methods for the thin film deposition process in vacuum deposition thin film technology only include simple monitoring of deposition rate, substrate film thickness and film component ratio, which cannot explore the quality of thin film formation during vacuum deposition and cannot meet the requirements for in-situ monitoring of film formation quality, resulting in low efficiency, low measurement accuracy and poor repeatability in the process of exploring vacuum deposited thin films with excellent optical properties. Existing photoluminescence and photoluminescence quantum efficiency (PLQE) tests are also only tested on the final film, and fail to achieve in-situ detection during the thin film deposition preparation process.

[0004] Based on this technical background, the present invention proposes a method and device for monitoring film quality during vacuum deposition of thin films. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention proposes a method and device for monitoring the quality of a thin film during vacuum deposition. The method calculates the relative photoluminescence quantum efficiency of the thin film during vacuum deposition based on the measured photoluminescence intensity of the thin film and the real-time intensity of the excitation light during vacuum deposition, monitors the film formation quality of the thin film through the relative photoluminescence quantum efficiency, and further determines the optimal deposition conditions.

[0006] In order to achieve the above object, the present invention provides a method for monitoring the quality of a thin film during vacuum deposition of the thin film in a first aspect, wherein the method comprises the following steps:

[0007] During the vacuum deposition of thin films, the photoluminescence intensity of the thin films and the real-time intensity of the excitation light are measured;

[0008] Calculating the relative photoluminescence quantum efficiency based on the photoluminescence intensity and the real-time intensity of the excitation light;

[0009] The film quality of the thin film is monitored based on the relative photoluminescence quantum efficiency to determine the optimal deposition conditions.

[0010] The second aspect of the present invention provides a device used in the above method, comprising: a photoluminescence detection unit, an excitation light real-time intensity monitoring unit, and a data processing and monitoring unit;

[0011] The photoluminescence detection unit is used to measure the photoluminescence intensity of the film during the vacuum deposition process;

[0012] The excitation light real-time intensity monitoring unit is used to measure the real-time intensity of the excitation light of the thin film during the vacuum deposition process;

[0013] The data processing and monitoring unit is used to calculate the relative photoluminescence quantum efficiency based on the photoluminescence intensity and the real-time intensity of the excitation light, and to monitor the film quality of the thin film based on the relative photoluminescence quantum efficiency to determine the best deposition conditions.

[0014] The effects of the present invention are:

[0015] (1) The method for monitoring the quality of a thin film during vacuum deposition of a thin film proposed in the present invention calculates the relative photoluminescence quantum efficiency of the thin film during vacuum deposition based on the measured photoluminescence intensity of the thin film during vacuum deposition and the real-time intensity of the excitation light, and monitors the photoelectric properties and photoelectric defects of the thin film through the relative photoluminescence quantum efficiency, and further determines the optimal deposition conditions.

[0016] (2) The method for monitoring the quality of thin films during the vacuum deposition process proposed in the present invention is aimed at the entire process of thin film preparation and realizes real-time monitoring of the film quality. It helps to obtain the optimal film forming conditions for preparing thin films based on vacuum deposition technology, which serves as an important parameter for measuring film performance, thereby comprehensively guiding thin film preparation.

[0017] (3) The method for monitoring film quality during vacuum deposition of thin films proposed in the present invention avoids interference from external noise and working frequency by setting the frequency of frequency modulation to be higher than 1 Hz and not equal to a multiple of the mains frequency, thereby improving the accuracy of monitoring film quality.

[0018] (4) The method for monitoring film quality during vacuum deposition of thin films proposed in the present invention avoids the influence of environmental noise during the monitoring of film quality by performing phase-locking processing or voltage reading on the photoluminescence reference signal and the photoluminescence detection signal, thereby further improving the accuracy of the relative photoluminescence quantum efficiency and achieving a real-time monitoring effect.

[0019] (5) The method for monitoring the quality of a thin film during vacuum deposition of a thin film proposed in the present invention sets a linear relationship between the electrical signals generated by the first detector and the second detector and the intensity of the light signal detected by them, and deducts their respective dark noises during data processing, thereby avoiding the influence of the detector itself on the monitoring effect.

[0020] (6) The method for monitoring the quality of a thin film during vacuum deposition of a thin film proposed in the present invention sets the ratio of the light intensities of the first light beam and the second light beam, thereby making the reflected light path and the incident light path of the excitation light more precisely controllable, thereby improving the accuracy of monitoring the quality of the thin film.

[0021] (7) The device for monitoring the quality of thin films during vacuum deposition of thin films proposed in the present invention sets the second detector at the focal position of the second lens, the frequency modulation unit at the light outlet of the excitation light source, and the coating device below the substrate, so that the transmission of the excitation light is more precise and controllable, thereby improving the thin film monitoring effect.

[0022] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0024] Figure 1 The figure is a schematic flow chart of the method for monitoring film quality during vacuum deposition of thin films proposed by the present invention.

[0025] Figure 2 A schematic structural diagram of a specific embodiment of a device for monitoring film quality during vacuum deposition of thin films proposed by the present invention;

[0026] Figure 3 A physical picture of a device for monitoring film quality during vacuum deposition of a thin film in Example 1 of the present invention;

[0027] Figure 4 A schematic diagram of a curve showing changes in the photoluminescence intensity and relative photoluminescence quantum efficiency of a thin film over time in the method for monitoring the quality of a thin film during vacuum deposition of a thin film in Example 1 of the present invention.

[0028] Figure 5 It is a schematic structural diagram of another specific implementation of the device for monitoring film quality in the vacuum deposition process of the film proposed by the present invention.

[0029] Figure 6This is a schematic structural diagram of a third specific implementation of the device for monitoring film quality during vacuum deposition of thin films proposed by the present invention.

[0030] Figure 7 It is a schematic structural diagram of a fourth specific implementation manner of the device for monitoring film quality during vacuum deposition of thin films proposed by the present invention.

[0031] Figure 8 The schematic diagram is a mechanism diagram of magnetron sputtering deposition of thin films in the method for monitoring film quality during vacuum deposition of thin films proposed in the present invention.

[0032] Fig. 9 The schematic diagram is a mechanism diagram of the molecular beam epitaxial growth and deposition of thin films in the method for monitoring the quality of thin films in the vacuum deposition process of thin films proposed by the present invention.

[0033] Description of reference numerals:

[0034] A0-photoluminescence detection unit, A1-excitation light real-time intensity monitoring unit, A2-light source frequency modulation and beam splitting unit; 1-excitation light source, 2-film coating device, 3-substrate, 4-1, first lens, 4-2, second lens, 5-second detector, 6-data processing and monitoring unit, 7-frequency modulation unit, 8-beam splitter, 9-short-pass filter, 10-first detector, 11-first voltage reading unit, 12-long-pass filter, 13-phase-locked amplifier, 14-second voltage reading unit; PL-thin film photoluminescence intensity, PLQE-photoluminescence quantum efficiency, Time-time. DETAILED DESCRIPTION

[0035] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0036] In the present disclosure, unless otherwise stated, directional words such as "upper" and "lower" generally refer to the upper and lower parts of a device in normal use. Figure 1 In the drawing direction, "inside" and "outside" refer to the outline of the device. In addition, the terms "first, second, third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first, second, third" may explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0037] The present invention provides a method for monitoring film quality during vacuum deposition of thin films, such as Figure 1-Figure 9 As shown, the method comprises the following steps:

[0038] During the vacuum deposition of thin films, the photoluminescence intensity of the thin films and the real-time intensity of the excitation light are measured;

[0039] The relative photoluminescence quantum efficiency is calculated based on the photoluminescence intensity and the real-time intensity of the excitation light;

[0040] The film quality was monitored based on the relative photoluminescence quantum efficiency to determine the optimal deposition conditions.

[0041] In the present invention, the relative photoluminescence quantum efficiency of the film during vacuum deposition is calculated based on the measured photoluminescence intensity of the film during vacuum deposition and the real-time intensity of the excitation light, and the photoelectric properties and photoelectric defects of the film are monitored by the relative photoluminescence quantum efficiency to further determine the optimal deposition conditions.

[0042] According to the present invention, the vacuum deposition thin film process is a process from when the substrate 3 is fed into the coating device 2 to when the substrate 3 leaves the coating device 2. Preferably, the vacuum deposition thin film process includes a pretreatment process of the substrate 3, and / or a pretreatment process of the thin film material, and / or a deposition process of the thin film material, and / or a post-treatment process of the finished thin film;

[0043] The film quality of the thin film refers to the photoelectric properties and / or film defect states of the thin film.

[0044] According to the present invention, the method further comprises the following steps:

[0045] Before vacuum deposition of the thin film or before the thin film material is deposited on the substrate 3, the dark noise of the first detector 10 is read as a first background signal after voltage reading, and the dark noise of the second detector 5 is read as a second background signal after voltage reading;

[0046] The excitation light is sequentially coupled by optical fiber, frequency modulated, and split to obtain a first light beam and a second light beam;

[0047] Before the thin film material is deposited on the substrate 3, the second light beam is adjusted to a light spot incident on the surface of the substrate 3, and the photoluminescence signal of the substrate 3 is sequentially focused, long-pass filtered, detected by the second detector 5, phase-locked or voltage read to obtain a third background signal;

[0048] The photoluminescence intensity of the film and the real-time intensity of the excitation light are measured including:

[0049] During the vacuum deposition of thin films, the first light beam is sequentially short-pass filtered, detected by the first detector 10, and the voltage is read, and then the first background signal is deducted to obtain the real-time intensity of the excitation light. ；

[0050] During the vacuum deposition of the thin film, a light spot is incident on the surface of the substrate 3 where the thin film is located, and the photoluminescence signal of the thin film is sequentially focused, long-pass filtered, and detected by the second detector 5 to obtain a photoluminescence detection signal;

[0051] The photoluminescence detection signal is phase-locked or voltage-read and then the second background signal and the third background signal are deducted to obtain the photoluminescence intensity.

[0052] In the present invention, the real-time monitoring of the film quality is achieved for the entire process of film preparation, which helps to obtain the optimal film forming conditions for preparing films based on vacuum deposition technology, and serves as an important parameter for measuring film performance, thereby comprehensively guiding film preparation.

[0053] In the present invention, by performing phase-locking processing or voltage reading on the photoluminescence reference signal and the photoluminescence detection signal, the influence of environmental noise in the process of monitoring the film quality is avoided, the accuracy of the relative photoluminescence quantum efficiency is further improved, and the real-time monitoring effect is achieved.

[0054] According to the present invention, the ratio of the photoluminescence intensity to the real-time intensity of the excitation light is used as the relative photoluminescence quantum efficiency;

[0055] The electrical signals generated by the first detector 10 and the second detector 5 are each linearly related to the intensity of the optical signal detected;

[0056] The wavelength of the excitation light is 200nm-2500nm, and is smaller than the photoluminescence wavelength of the film;

[0057] The area of ​​the light spot is adapted to the area of ​​the film;

[0058] The ratio of the light intensity of the first light beam to that of the second light beam is 1 / 3-3 / 4.

[0059] In the present invention, the electrical signals generated by the first detector 5 and the second detector 10 are set to have a linear relationship with the intensity of the light signal detected by them, and the respective dark noises are deducted during data processing, thereby avoiding the influence of the detector itself on the monitoring effect.

[0060] In the present invention, by setting the ratio of the light intensities of the first light beam and the second light beam, the reflected light path and the incident light path of the excitation light are made more accurately controllable, thereby improving the accuracy of monitoring the film quality.

[0061] In the present invention, in order to ensure effective monitoring of the film quality, the area of ​​the light spot can be dynamically adjusted to adapt to the area of ​​the film.

[0062] Preferably, the spectral response range of the first detector (10) and the second detector (5) are both 200nm-2500nm;

[0063] The frequency of the FM is higher than 1Hz and is not equal to a multiple of the mains frequency.

[0064] In the present invention, when the wavelength of the excitation light is 300nm-375nm, the long-wave cut-off wavelength of the short-pass filter is 395nm-405nm, and the short-wave cut-off wavelength of the long-pass filter is 395nm-405nm; when the wavelength of the excitation light is 400nm-445nm, the long-wave cut-off wavelength of the short-pass filter is 495nm-505nm, and the short-wave cut-off wavelength of the long-pass filter is 495nm-505nm.

[0065] In the present invention, by setting the frequency of frequency modulation to be higher than 1 Hz and not equal to a multiple of the mains frequency, interference from external noise and working frequency is avoided, thereby improving the monitoring accuracy of film quality.

[0066] Preferably, the optical path used to obtain the third background signal and the photoluminescence intensity of the film is a reflection mode or a transmission mode;

[0067] When the optical path used to obtain the third background signal and the photoluminescence intensity of the thin film is in reflection mode, the substrate of the substrate 3 is transparent or non-transparent to the excitation light and the photoluminescence of the thin film;

[0068] When the optical path used to obtain the third background signal and the photoluminescence intensity of the thin film is in transmission mode, the substrate of the substrate 3 is transparent to the excitation light and the photoluminescence of the thin film;

[0069] Vacuum deposition is any one of vacuum evaporation coating, magnetron sputtering, and molecular beam epitaxial growth.

[0070] The present invention also provides a device used in the above method, comprising: a photoluminescence detection unit A0, an excitation light real-time intensity monitoring unit A1, and a data processing monitoring unit 6;

[0071] The photoluminescence detection unit A0 is used to measure the photoluminescence intensity of the film during the vacuum deposition process;

[0072] The excitation light real-time intensity monitoring unit A1 is used to measure the real-time intensity of the excitation light of the thin film during the vacuum deposition process;

[0073] The data processing and monitoring unit 6 is used to calculate the relative photoluminescence quantum efficiency based on the photoluminescence intensity and the real-time intensity of the excitation light, and to monitor the film quality of the thin film based on the relative photoluminescence quantum efficiency to determine the best deposition conditions.

[0074] According to the present invention, the device further comprises a light source frequency modulation beam splitting unit A2 and a substrate 3;

[0075] The light source frequency modulation beam splitting unit A2 comprises an excitation light source 1, a frequency modulation unit 7 and a beam splitter 8;

[0076] The excitation light real-time intensity monitoring unit A1 includes a short-pass filter 9, a first detector 10 and a first voltage reading unit 11;

[0077] The photoluminescence detection unit A0 includes a first lens 4-1, a second lens 4-2, a long-pass filter 12, a second detector 5, a lock-in amplifier 13 or a second voltage reading unit 14;

[0078] The excitation light source 1, the frequency modulation unit 7, the beam splitter 8, and the first lens 4-1 are sequentially arranged on the incident light path of the excitation light source 1;

[0079] The short-pass filter 9, the first detector 10, and the first voltage reading unit 11 are sequentially arranged on the reflected light path of the excitation light source 1;

[0080] The second lens 4-2, the long-pass filter 12, the second detector 5, the lock-in amplifier 13 or the second voltage reading unit 14 are sequentially arranged on the light path of collecting the photoluminescence of the film;

[0081] The frequency modulation unit 7 is provided with a reference frequency modulation outlet, and the frequency modulation reference outlet is connected to the reference frequency modulation signal input port of the phase-locked amplifier 13;

[0082] The outlets of the first voltage reading unit 11 , the second voltage reading unit 14 and the lock-in amplifier 13 are electrically connected to the data processing unit 6 , respectively.

[0083] Preferably, the second detector 5 is located at the focal position of the second lens 4-2;

[0084] The frequency modulation unit 7 is located at the light outlet of the excitation light source 1 and is used to adjust the excitation light frequency of the excitation light source 1;

[0085] The coating device 2 is located below the substrate 3 and is used to deposit a thin film onto the substrate 3 in a vertical manner.

[0086] In the present invention, by setting the second detector 5 at the focal position of the second lens 4-2, the frequency modulation unit 7 at the light outlet of the excitation light source 1, and the coating device 2 below the substrate 3, the transmission of the excitation light is more precise and controllable, thereby improving the thin film monitoring effect.

[0087] Preferably, the data processing unit 6 is any one of a computer, a single chip microcomputer, a DSP and an FPGA;

[0088] The first voltage reading unit 11, the second voltage reading unit 14 and the lock-in amplifier 13 are all electrically connected to the data processing unit 6 through their own independent GPIB interface, USB interface, or RS232 interface;

[0089] The frequency modulation unit 7 and the second detector 5 are connected to the signal input port of the lock-in amplifier 13 through their own independent BNC radio frequency connection lines.

[0090] Preferably, the frequency modulation unit 7 is a chopper or a signal generator;

[0091] The first voltage reading unit 11 and the second voltage reading unit 14 are each independently selected from a digital source meter or an oscilloscope;

[0092] The excitation light source 1 is any one of a single-wavelength laser, a single-wavelength halogen lamp, a single-wavelength excitation light generated by a wide-spectrum light source and a monochromator, and a single-wavelength excitation light generated by a wide-spectrum light source and a bandpass filter.

[0093] The present invention is described in more detail below through a specific embodiment.

[0094] Example 1

[0095] This embodiment provides a device for monitoring the quality of a thin film during vacuum deposition of a thin film. Figure 1-Figure 3 As shown, it includes: a photoluminescence detection unit A0, an excitation light real-time intensity monitoring unit A1, and a data processing and monitoring unit 6;

[0096] The photoluminescence detection unit A0 is used to measure the photoluminescence intensity of the film during the vacuum deposition process;

[0097] The excitation light real-time intensity monitoring unit A1 is used to measure the real-time intensity of the excitation light of the thin film during the vacuum deposition process;

[0098] The data processing and monitoring unit 6 is used to calculate the relative photoluminescence quantum efficiency based on the photoluminescence intensity and the real-time intensity of the excitation light, and to monitor the film quality of the thin film based on the relative photoluminescence quantum efficiency to determine the best deposition conditions.

[0099] According to the present invention, the device further comprises a light source frequency modulation beam splitting unit A2 and a substrate 3;

[0100] The light source frequency modulation beam splitting unit A2 comprises an excitation light source 1, a frequency modulation unit 7 and a beam splitter 8;

[0101] The excitation light real-time intensity monitoring unit A1 includes a short-pass filter 9, a first detector 10 and a first voltage reading unit 11;

[0102] The photoluminescence detection unit A0 includes a first lens 4-1, a second lens 4-2, a long-pass filter 12, a second detector 5, a lock-in amplifier 13 or a second voltage reading unit 14;

[0103] The excitation light source 1, the frequency modulation unit 7, the beam splitter 8, and the first lens 4-1 are sequentially arranged on the incident light path of the excitation light source 1;

[0104] The short-pass filter 9, the first detector 10, and the first voltage reading unit 11 are sequentially arranged on the reflected light path of the excitation light source 1;

[0105] The second lens 4-2, the long-pass filter 12, the second detector 5, and the lock-in amplifier 13 are sequentially arranged on the light collecting path of the photoluminescence of the film;

[0106] The frequency modulation unit 7 is provided with a reference frequency modulation outlet, and the frequency modulation reference outlet is connected to the reference frequency modulation signal input port of the phase-locked amplifier 13;

[0107] The outlets of the first voltage reading unit 11 and the lock-in amplifier 13 are electrically connected to the data processing unit 6 respectively;

[0108] The second detector 5 is located at the focal position of the second lens 4-2;

[0109] The frequency modulation unit 7 is located at the light outlet of the excitation light source 1 and is used to adjust the excitation light frequency of the excitation light source 1;

[0110] The coating device 2 is located below the substrate 3 and is used to deposit a thin film onto the substrate 3 in a vertical manner;

[0111] The data processing unit 6 is a computer;

[0112] The first voltage reading unit 11 and the lock-in amplifier 13 are both electrically connected to the data processing unit 6 through their own independent GPIB interfaces;

[0113] The frequency modulation unit 7 and the second detector 5 are connected to the signal input port of the lock-in amplifier 13 through their own independent BNC radio frequency connection lines;

[0114] The frequency modulation unit 7 is a signal generator;

[0115] The first voltage reading unit 11 is an oscilloscope;

[0116] The excitation light source 1 is a single-wavelength laser;

[0117] This embodiment further includes a coating device 2 for depositing a thin film on a substrate 3; the evaporation source of the coating device 2 is multi-source evaporation.

[0118] This embodiment provides a method for monitoring the quality of a thin film during vacuum deposition of the thin film. Figure 1-Figure 4 As shown, the method comprises the following steps:

[0119] During the vacuum deposition of thin films, the photoluminescence intensity of the thin films and the real-time intensity of the excitation light are measured;

[0120] The relative photoluminescence quantum efficiency is calculated based on the photoluminescence intensity and the real-time intensity of the excitation light;

[0121] Monitor film quality based on relative photoluminescence quantum efficiency to determine optimal deposition conditions;

[0122] In this embodiment, the vacuum deposition process of the thin film includes a pretreatment process of the substrate 3, a pretreatment process of the thin film material, a deposition process of the thin film material and a post-treatment process of the finished thin film;

[0123] In this embodiment, the film quality of the film is the photoelectric properties and defect state of the film;

[0124] The method further comprises the following steps:

[0125] Before vacuum deposition of the film, the dark noise of the first detector 10 is measured as a first background signal after voltage reading, and the dark noise of the second detector 5 is measured as a second background signal after voltage reading;

[0126] The excitation light is sequentially coupled by optical fiber, frequency modulated, and split to obtain a first light beam and a second light beam;

[0127] Before the thin film material is deposited on the substrate 3, the second light beam is adjusted to a light spot incident on the surface of the substrate 3, and the photoluminescence signal of the substrate 3 is sequentially focused, long-pass filtered, detected by the second detector 5, phase-locked or voltage read to obtain a third background signal;

[0128] The photoluminescence intensity of the film and the real-time intensity of the excitation light are measured including:

[0129] During the vacuum deposition of thin films, the first light beam is sequentially short-pass filtered, detected by the first detector 10, and the voltage is read, and then the first background signal is deducted to obtain the real-time intensity of the excitation light. ；

[0130] During the vacuum deposition of the thin film, a light spot is incident on the surface of the substrate 3 where the thin film is located, and the photoluminescence signal of the thin film is sequentially focused, long-pass filtered, and detected by the second detector 5 to obtain a photoluminescence detection signal;

[0131] After the photoluminescence detection signal is read through phase lock, the second background signal and the third background signal are deducted to obtain the photoluminescence intensity;

[0132] The ratio of the photoluminescence intensity to the real-time intensity of the excitation light is taken as the relative photoluminescence quantum efficiency;

[0133] The electrical signals generated by the first detector 10 and the second detector 5 are each linearly related to the intensity of the optical signal detected;

[0134] The wavelength of the excitation light is 375 nm, which is smaller than the photoluminescence wavelength of the film;

[0135] The area of ​​the light spot is adapted to the area of ​​the film;

[0136] The ratio of the light intensity of the first light beam to the light intensity of the second light beam is 1 / 2;

[0137] In this embodiment, in order to ensure effective monitoring of the film quality, the area of ​​the light spot can be dynamically adjusted to adapt to the area of ​​the film;

[0138] The spectral response range of the first detector (10) and the second detector (5) are both 200nm-2500nm;

[0139] The frequency of FM is 10Hz.

[0140] In this embodiment, the long-wave cutoff wavelength of the short-pass filter is 400 nm, and the short-wave cutoff wavelength of the long-pass filter is 400 nm;

[0141] The optical path used to obtain the third background signal and the photoluminescence intensity of the film is a reflection mode;

[0142] The substrate of the substrate 3 is non-transparent to the excitation light and the photoluminescence of the film;

[0143] Vacuum deposition is vacuum evaporation coating.

[0144] like Figure 4 As shown, in the process of thin film deposition, this embodiment accurately detects the changes of the thin film photoluminescence intensity and the relative photoluminescence quantum efficiency over time, thereby achieving effective detection of the photoelectric performance of the thin film.

[0145] Example 2

[0146] In this embodiment, the difference from the embodiment 1 is that in the device for monitoring the quality of the thin film during the vacuum deposition process, the first voltage reading unit 11 is an oscilloscope or a digital source meter, the frequency modulation unit 7 is a chopper, and the rest is the same as the embodiment 1, such as Figure 2 shown.

[0147] Example 3

[0148] In this embodiment, the difference from Embodiment 1 is that the wavelength of the short-wavelength light in the method for monitoring the quality of the thin film during the vacuum deposition process is 445 nm; the long-wavelength cut-off wavelength of the short-pass filter is 500 nm, and the short-wavelength cut-off wavelength of the long-pass filter is 500 nm, and the rest is the same as Embodiment 1, such as Figure 2 shown.

[0149] Example 4

[0150] In this embodiment, the difference from the embodiment 1 is that the evaporation source in the device for monitoring the quality of the thin film during the vacuum deposition process is a single-source evaporation, and the rest is the same as the embodiment 1, such as Figure 5 shown.

[0151] Example 5

[0152] In this embodiment, the difference from the embodiment 1 is that the excitation light source 1 in the monitoring device for the quality of the thin film during the vacuum deposition process is a combination of a monochromator and a xenon lamp, and the rest is the same as the embodiment 1, such as Figure 6 shown.

[0153] Example 6

[0154] In this embodiment, the difference from the embodiment 1 is that the photoluminescence intensity of the film is measured in the method for monitoring the quality of the film during the vacuum deposition process using a transmission mode, the substrate 3 is transparent, and the rest is the same as the embodiment 1, such as Figure 7 shown.

[0155] Example 7

[0156] In this embodiment, the difference from the embodiment 1 is that the phase-locked amplifier 13 in the monitoring device for the quality of the thin film during the vacuum deposition process is replaced with a second voltage reading unit 14, and the rest is the same as the embodiment 1, such as Figure 1 shown.

[0157] Example 8

[0158] In this embodiment, the difference from the embodiment 1 is that the vacuum deposition in the method for monitoring the film quality during the vacuum deposition of the film is magnetron sputtering, and the rest is the same as the embodiment 1, such as Figure 2 , Figure 8 shown. Fig. 9 A schematic diagram showing the mechanism of thin film deposition using magnetron sputtering.

[0159] Example 9

[0160] In this embodiment, the difference from the embodiment 1 is that in the method for monitoring the quality of the thin film during the vacuum deposition of the thin film, the vacuum deposition is molecular beam epitaxial growth, and the rest is the same as the embodiment 1, such as Figure 2 , Fig. 9 shown. Fig. 9 A schematic diagram showing the mechanism of thin film deposition using molecular beam epitaxy.

[0161] In the above embodiments, the photoluminescence, light intensity monitoring and relative photoluminescence quantum efficiency testing are combined with the vacuum thin film deposition technology to achieve in-situ monitoring of the film quality during the vacuum thin film deposition process.

[0162] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for monitoring film quality during vacuum deposition of thin films, characterized in that: The method comprises the following steps: During the vacuum deposition of thin films, the photoluminescence intensity of the thin films and the real-time intensity of the excitation light are measured; Calculating the relative photoluminescence quantum efficiency based on the photoluminescence intensity and the real-time intensity of the excitation light; The film quality of the thin film is monitored based on the relative photoluminescence quantum efficiency to determine the optimal deposition conditions.

2. The method according to claim 1, characterized in that: The vacuum thin film deposition process is a process from the time when the substrate (3) is fed into the coating device (2) to the time when the substrate (3) leaves the coating device (2). Preferably, the vacuum thin film deposition process includes a pretreatment process of the substrate (3), and / or a pretreatment process of the thin film material, and / or a deposition process of the thin film material, and / or a post-treatment process of the finished thin film; The film quality of the film is the photoelectric performance and / or film defect state of the film. 。 3. The method according to claim 2, characterized in that The method further comprises the following steps: Before vacuum deposition of a thin film or before deposition of the thin film material onto a substrate (3), the dark noise of the first detector (10) is measured and read as a first background signal after voltage reading, and the dark noise of the second detector (5) is measured and read as a second background signal after voltage reading; The excitation light is sequentially coupled by optical fiber, frequency modulated, and split to obtain a first light beam and a second light beam; Before the thin film material is deposited on the substrate (3), the second light beam is adjusted to a light spot incident on the surface of the substrate (3), and the photoluminescence signal of the substrate (3) is sequentially focused, long-pass filtered, detected by a second detector (5), phase-locked or voltage-read to obtain a third background signal; The method of measuring the photoluminescence intensity of the film and the real-time intensity of the excitation light comprises: During the vacuum deposition of thin films, the first light beam is sequentially short-pass filtered, detected by a first detector (10), and voltage read, and then the first background signal is deducted to obtain the real-time intensity of the excitation light. ； During the vacuum deposition of the thin film, the light spot is incident on the surface of the substrate (3) where the thin film is located, and the photoluminescence signal of the thin film is sequentially focused, long-pass filtered, and detected by a second detector (5) to obtain a photoluminescence detection signal; The photoluminescence detection signal is subjected to phase locking or voltage reading, and then the second background signal and the third background signal are deducted to obtain the photoluminescence intensity.

4. The method according to claim 3, characterized in that The ratio of the photoluminescence intensity to the real-time intensity of the excitation light is used as the relative photoluminescence quantum efficiency; The electrical signals generated by the first detector (10) and the second detector (5) are each linearly related to the intensity of the optical signal detected by them; The wavelength of the excitation light is 200nm-2500nm, and is smaller than the photoluminescence wavelength of the film; The area of ​​the light spot is adapted to the area of ​​the film; The ratio of the light intensities of the first light beam and the second light beam is 1:9 to 9:

1.

5. The method according to claim 3, characterized in that: The spectral response range of the first detector (10) and the second detector (5) are both 200nm-2500nm; The frequency of the frequency modulation is higher than 1 Hz and is not equal to a multiple of the mains frequency.

6. The method according to claim 3, characterized in that The optical path used to obtain the third background signal and the photoluminescence intensity of the film is a reflection mode or a transmission mode; When the optical path used to obtain the third background signal and the photoluminescence intensity of the thin film is in a reflection mode, the substrate of the substrate (3) is transparent or non-transparent to the excitation light and the photoluminescence of the thin film; When the optical path used to obtain the third background signal and the photoluminescence intensity of the thin film is in transmission mode, the substrate of the substrate (3) is transparent to the excitation light and the photoluminescence of the thin film; The vacuum deposition is any one of vacuum evaporation coating, magnetron sputtering, and molecular beam epitaxial growth.

7. A device used in the method according to any one of claims 1 to 6, characterized in that: include: Photoluminescence detection unit (A0), excitation light real-time intensity monitoring unit (A1), data processing monitoring unit (6); The photoluminescence detection unit (A0) is used to measure the photoluminescence intensity of the film during the vacuum deposition process; The excitation light real-time intensity monitoring unit (A1) is used to measure the real-time intensity of the excitation light of the thin film during the vacuum deposition process; The data processing and monitoring unit (6) is used to calculate the relative photoluminescence quantum efficiency based on the photoluminescence intensity and the real-time intensity of the excitation light, and to monitor the film forming quality of the thin film based on the relative photoluminescence quantum efficiency to determine the optimal deposition conditions.

8. The device according to claim 7, characterized in that The device also includes a light source frequency modulation beam splitting unit (A2) and a substrate (3); The light source frequency modulation beam splitting unit (A2) comprises an excitation light source (1), a frequency modulation unit (7) and a beam splitter (8); The excitation light real-time intensity monitoring unit (A1) comprises a short-pass filter (9), a first detector (10) and a first voltage reading unit (11); The photoluminescence detection unit (A0) comprises a first lens (4-1), a second lens (4-2), a long-pass filter (12), a second detector (5), a lock-in amplifier (13) or a second voltage reading unit (14); The excitation light source (1), the frequency modulation unit (7), the beam splitter (8), and the first lens (4-1) are sequentially arranged on the incident light path of the excitation light source (1); The short-pass filter (9), the first detector (10), and the first voltage reading unit (11) are sequentially arranged on the reflected light path of the excitation light source (1); The second lens (4-2), the long-pass filter (12), the second detector (5), the lock-in amplifier (13) or the second voltage reading unit (14) are sequentially arranged on a light collection path of the photoluminescence of the film; The frequency modulation unit (7) is provided with a reference frequency modulation output, and the frequency modulation reference output is connected to a reference frequency modulation signal input port of the lock-in amplifier (13); The outlets of the first voltage reading unit (11), the second voltage reading unit (14) and the lock-in amplifier (13) are electrically connected to the data processing unit (6) respectively.

9. The device according to claim 8, characterized in that The second detector (5) is located at the focal position of the second lens (4-2); The frequency modulation unit (7) is located at the light outlet of the excitation light source (1) and is used to adjust the excitation light frequency of the excitation light source (1); The film coating device (2) is located below the substrate (3) and is used to deposit the thin film onto the substrate (3) in a vertical manner.

10. The device according to claim 9, characterized in that The data processing unit (6) is any one of a computer, a single chip microcomputer, a DSP and an FPGA; The first voltage reading unit (11), the second voltage reading unit (14) and the lock-in amplifier (13) are all electrically connected to the data processing unit (6) via respective independent GPIB interfaces, or USB interfaces, or RS232 interfaces; The frequency modulation unit (7) and the second detector (5) are both connected to the signal input port of the lock-in amplifier (13) via independent BNC radio frequency connection lines.

11. The device according to claim 10, characterized in that The frequency modulation unit (7) is a chopper or a signal generator; The first voltage reading unit (11) and the second voltage reading unit (14) are each independently selected from a digital source meter or an oscilloscope; The excitation light source (1) is any one of a single-wavelength laser, a single-wavelength halogen lamp, a single-wavelength excitation light generated by a wide-spectrum light source and a monochromator, and a single-wavelength excitation light generated by a wide-spectrum light source and a bandpass filter.

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